Adaptive light detection for arc mitigation systems

Abstract

A controller-based detection system configured to adaptively learn to distinguish between detected light that is indicative of an arc fault event and detected light that is not related to an arc fault event. In particular, the detection system is configured to observe the electrical power system as it is operated under various conditions to induce light events that are unrelated to arc fault events. Using the observed information about the light events that are unrelated to arc fault events, the detection system determines one or more detection algorithms. During normal operation of the electrical power system, the adaptively determined one or more detection algorithms are utilized to identify arc fault events in the electrical power system.

What is claimed is: 
     
       1. An arc fault protection system for an electrical power system, the arc fault protection system comprising:
 a light sensor configured to detect a first visible light event and generate a first light signal indicative of the detected first visible light event, the first visible light event being a non-arc fault event triggered via operation of the system, the light sensor further configured to detect a second light visible event and generate a second light signal indicative of the detected second visible light event; 
 a controller in communication with the light sensor, the controller being configured to:
 receive and process the first light signal to determine an arc detection algorithm, 
 receive and process the second light signal to determine whether the second light signal is indicative of an arc fault event using the arc detection algorithm, and 
 generate an arc fault signal in response to the controller determining that the second light signal is indicative of an arc fault event; and 
 
 a protection device in communication with the controller, the protection device being configured to mitigate the arc fault event in response to the protection device receiving the arc fault signal from the controller. 
 
     
     
       2. The arc fault protection system of  claim 1 , wherein the arc detection algorithm includes a fault criteria. 
     
     
       3. The arc fault protection system of  claim 2 , wherein the controller is configured to determine the fault criteria based on the first light signal. 
     
     
       4. The arc fault protection system of  claim 2 , wherein the controller is configured to determine a characteristic of the second light signal and compare the determined characteristic to the fault criteria to determine whether the second light signal is indicative of an arc fault event. 
     
     
       5. The arc fault protection system of  claim 4 , wherein the characteristic is determined by a neural network. 
     
     
       6. The arc fault protection system of  claim 5 , wherein the controller is configured to determine the neural network based on the first light signal. 
     
     
       7. The arc fault protection system of  claim 4 , wherein the characteristic includes a plurality of characteristics including a magnitude of light intensity and a rate of change in magnitude of light intensity. 
     
     
       8. The arc fault protection system of  claim 2 , wherein the fault criteria includes a first light signature based on the first light signal. 
     
     
       9. The arc fault protection system of  claim 8 , wherein the controller is further configured to:
 determine a second light signature for the second light signal; 
 compare the second light signature to the first light signature; and 
 based on the comparison, determine whether the second light signal is indicative of an arc fault event. 
 
     
     
       10. The arc fault protection system of  claim 1 , wherein the controller is further configured to verify the determination of the arc detection algorithm. 
     
     
       11. The arc fault protection system of  claim 1 , wherein the controller is further configured to adaptively adjust the arc detection algorithm in response to a changed condition of the arc fault protection system or a changed configuration of a system protected by the arc fault protection system. 
     
     
       12. A method for adaptively identifying an arc fault event in an electrical power system, the method comprising:
 operating the electrical power system to generate a first visible light event triggered by a non-arc fault event; 
 detecting the first visible light event with a light sensor; 
 generating a first light signal indicative of the detected first visible light event; 
 processing, using a controller, the first light signal to determine an arc fault criterion; 
 operating the electrical power system to generate a second visible light event; 
 detecting the second visible light event with the light sensor; 
 generating a second light signal indicative of the second visible light event; 
 processing the second light signal to determine a characteristic of the second light signal; and 
 comparing the characteristic to the arc fault criterion to determine whether the second light signal is indicative of an arc fault event. 
 
     
     
       13. The method of  claim 12 , wherein the characteristic of the second light signal includes one or more of a magnitude of light intensity, a rate of change of a intensity magnitude, a frequency, a wavelength, a duration, or a direction or angle of incidence of light incident on the light sensor. 
     
     
       14. The method of  claim 12 , wherein the criterion includes one or more of a threshold value, a range of threshold values, or a predetermined light signature. 
     
     
       15. The method of  claim 12  further comprising receiving from an input device an input indicative of the source of the first visible light event. 
     
     
       16. The method of  claim 12  further comprising storing information about the second light signal in a memory if the second light signal is determined not to be indicative of an arc fault event. 
     
     
       17. The method of  claim 12 , further comprising adaptively adjusting the arc fault criterion in response to a changed condition of the arc fault protection system or a changed configuration of a system protected by the arc fault protection system. 
     
     
       18. An arc fault protection system for an electrical power system, the arc fault protection system comprising:
 a light sensor configured to detect a first light event and generate a first light signal indicative of the detected first light event, the first light event being a non-arc fault event, the light sensor further configured to detect a second light event and generate a second light signal indicative of the detected second light event; 
 a controller in communication with the light sensor, the controller being configured to:
 determine an arc detection algorithm based on the first light signal, 
 verify the arc detection algorithm based on an induced non-arc fault light event, the verification including an error signal that is generated if the induced non-arc fault light event is determined to be an arc fault light event based on the arc detection algorithm; and 
 determine whether the second light signal is indicative of the arc fault event based on the arc detection algorithm and generate a fault signal if the controller determines that the second signal is indicative of the arc fault event; and 
 
 a protection device in communication with the controller, the protection device being configured to mitigate the arc fault event in response to the protection device receiving the fault signal from the controller. 
 
     
     
       19. The arc fault protection system of  claim 18  further comprising an input device configured to selectively cause the controller to determine the arc detection algorithm, verify the arc detection algorithm, or determine whether the second light signal is indicative of the arc fault event. 
     
     
       20. The arc fault protection system of  claim 18 , wherein the arc detection algorithm includes a neural network. 
     
     
       21. The arc fault protection system of  claim 18 , wherein the arc detection algorithm includes a comparison of the first light signature corresponding to the first light signal and a second light signature corresponding to the second light signal. 
     
     
       22. The arc fault protection system of  claim 18 , wherein the light sensor is configured to detect the first light event and the second light event as visible light, the first light signal and the second light signal being indicative of the visible light detected by the light sensor for the first light event and the second light event, respectively.